2009-05-26

It's sometimes nice to see the changes you've made to a file. If the file is
under version control, you can use the 'diff'-features of the version
control system of course; or you can use diff-buffer-with-file to compare
your buffer with the version on disk. That obviously only. works when you
haven't saved the file yet.

Anyway, a bit easier, straighforward way may be to use
highlight-changes-mode. With that mode, emacs can give a special color to
parts of the text that you have changed.